Billaea brevicauda Zhang et Shima

Zhang, Chun-Tian, Shima, Hiroshi, Wang, Qiang & Tschorsnig, Hans-Peter, 2015, A review of Billaea Robineau-Desvoidy of the eastern Palearctic and Oriental regions (Diptera: Tachinidae), Zootaxa 3949 (1), pp. 1-40 : 6-7

Billaea brevicauda Zhang et Shima sp. nov.

Figs. 5–8 , 65 , 74

Diagnosis. Facial carina developed, arista short plumose, 3 katepisternal setae, fore tarsi longer than head height, hind tibia with 2–3 stronger setae among a row of rather closely set anterodorsal setae, abdomen reddish brown with thin grayish pruinosity except for dark tergite 5, tergite 3 without median marginal seta and cerci short.

Description. Body length 12.7–14.0 mm.

Male. Head ( Figs. 65 , 74 ). Dark brown to black in ground color, broadly reddish on gena and lower parafacial, with grayish white pruinosity; frontal vitta black; lunule brown; antenna black, arista dark brown; palpus reddish yellow. Vertex 0.14–0.17 of head width; frontal vitta strongly widened anteriorly, about 3 times as wide as frontoorbital plate; parafacial 2.5–3 times as wide as flagellomere 1; facial carina developed, short and distinct, lower margin of face well protruding forward; genal height 0.4–0.45 of eye height. Inner vertical seta 0.4–0.5 times as long as eye height; outer vertical seta indistinguishable from upper occipital setae; fronto-orbital plate with 2–3 rows of fine and rather dense hairs which do not descend below level of lunule; parafacial bare; 11–12 pairs of inclinate frontal setae, upper ones about as long as ocellar seta and inner vertical seta. Flagellomere 1 3.5–4 times as long as pedicel; pedicel with 1–2 long setae, which are about as long as antenna; arista short plumose, total width including plumosity 1–1.5 times as wide as flagellomere 1. Prementum slightly more than 1/2 of eye height, 5–6 times as long as wide; palpus about twice as long as flagellomere 1.

Thorax. Black in ground color, scutum covered with thin grayish white pruinosity, with 5 longitudinal black vittae, outer vitta 1/4–1/3 as wide as pruinose portion between outer and inner vittae; scutellum dark brown to black, sometimes brown apically. Prosternum about twice as long as wide; Five to six postpronotal setae, 3 strong basal setae arranged in a triangle; 2–3 presutural and 2 postsutural acrostichal setae; 3 presutural and 4 postsutural dorsocentral setae; 3 postsutural intra-alar setae; 4 supra-alar setae, first and third ones short; 3 katepisternal setae; katepimeron rather sparsely haired; scutellum sometimes with 1–2 additional fine setae between basal and subapical setae, and 2 pairs of discal setae. Wing. Hyaline, slightly tinged with pale brown throughout; tegula dark brown, basicosta reddish brown to reddish yellow; lower calypter white; halter brown on basal half and reddish yellow apically. Relative lengths of 2nd, 3rd and 4th costal sectors approximately as 3:5.5:2.5; vein M from dm-cu crossvein to its bend 2.0–2.3 times distance between the bend and wing margin. Legs. Dark brown, tibiae brown to dark brown, pulvilli yellowish. Fore claws and pulvilli subequal in length to or slightly longer than 5th tarsomere; fore tarsi longer than head height; fore tibia with a row of anterodorsal setae on basal 3/4 and 2 posterior setae; mid tibia with 1–2 anterodorsal, 1 posterodorsal and 1 ventral setae, all setae rather fine and short; hind tibia with a row of rather densely set anterodorsal setae, 2–3 strong setae among them, 3 posterodorsal and 2–3 ventral setae.

Abdomen. Ovate, reddish brown to brown in ground color, mid dorsal longitudinal portion of syntergite 1+2 to tergite 4 and entire tergite 5 black, with thin grayish pruinosity on entire dorsum, the pruinosity thinner posteriorly on each tergite and with tessellate appearance with direction of light. Dense short fine recumbent hairs on tergites 3 and 4, longer and erect hairs on tergite 5; syntergite 1+2 and tergite 3 without median marginal setae, each with 1– 2 pairs of lateral marginal setae, seldom 1–2 fine and short median marginal setae on tergite 3; tergite 5 with regular rows of rather fine discal and strong marginal setae. Male terminalia ( Figs. 5–8 ). Sternite 5 quadrangular, posterior lobes wide and rounded apically, V-shaped median cleft deep. Cerci short, wide at base and narrowed at distal half, pointed apically in caudal view; pregonite long and strongly bent ventrally near middle; postgonite shorter than basiphallus; distiphallus long, sclerotized basal part slightly shorter than membranous apical part.

Female. Vertex about 1/3 of head width; outer vertical seta about 1/2 as long as inner vertical seta; 1 outwardly directed prevertical seta; 2 subequally long proclinate orbital setae; 7 inclinate frontal setae, shorter than proclinate orbital setae and inner vertical seta; claws and pulvilli shorter than 5th tarsomere; mid tibia with 3–4 long anterodorsal and 2 short posterodorsal setae; abdomen dark brown to black, with gray pruinosity; tergite 3 with 2 median marginal setae. Other characters are same as in male.

Type material. Holotype ♂, CHINA, Haitong, 3250 m, Mangkang (98°40′E, 29°41′N), Xizang Autonomous Region (= Tibet), 11.viii.1982, X.-Z. Zhang ( IZCAS). Paratypes. CHINA. Sichuan: 2♂♂, Yajiang, 3300 m, 25– 28.viii.1982, X.-Z. Zhang; 1♂, Yidun, 3500 m, Batang, 16.viii.1982, H.-C. Chai ( IZCAS); 2♂♂, 1♀, Yajiang, 2800–3100 m, 23.viii.1993, H. Shima, A. Nakanishi ( BLKU), 1♂, same locality and date as above, X. Lin; 1♂, Geka-Echu Mountain, 2260–4100 m, Daocheng, 14.vii.2006, L.-Y. Feng ( SYNU). Xizang: Same locality as holotype, 8–11.viii.1982, 3♂♂, S.-Y. Wang, 1♂, X.-Z. Zhang, 3♂♂, H.-C. Chai. Yunnan: 1♂, Chongjianghe, 2400 m, Zhongdian, 8.viii.1984, S.-Y. Wang ( IZCAS).

Etymology. The specific epithet is taken from a character of this species (the short cerci); it is composed from the Latin adjective brevis (short) plus the noun cauda (tail or appendage).

Distribution. China (Sichuan, Xizang, Yunnan).

Remarks. This species appears to belong to Dinera in having distinct facial carina, long fore tarsi and 2–3 strong setae among row of anterodorsal setae, but here we regard it as a member of Billaea by fronto-orbital plate with dense hairs, and tergites 3 and 4 without median discal setae. The new species is similar to B. fortis in appearance with distinct facial carina, lower margin of face well protruding forward, 3 katepisternal setae, and abdomen with a black median longitudinal vitta on tergites. But the former differs from the latter in having plumose arista, longer fore tarsi, hind tibia of male with 2–3 strong setae among a row of rather densely set anterodorsal setae and abdominal tergite 3 lacking median marginal setae, and reddish brown to brown abdomen.

Figures

FIGURES 1 – 15. 1 – 4. Billaea atkinsoni (Baranov). 5 – 8. B. brevicauda sp. nov. 9 – 11. B. carinata sp. nov. 12 – 15. B. chinensis sp. nov. 1 – 2, 5 – 6, 9 – 10, 12 – 13. Cerci, surstyli and epandrium of male in lateral and caudal views. 3, 7, 11, 14. Ejaculatory apodeme (except 3), aedeagal apodeme, hypandrium, pregonite, postgonite, basiphallus, distiphallus in lateral view. 4, 8, 15. Sternite 5. Scale bars = 0.25 mm.

FIGURES 64 – 72. Billaea spp., heads of male in lateral view. 64. B. atkinsoni (Baranov). 65. B. brevicauda sp. nov. 66. B. carinata sp. nov. 67. B. chinensis sp. nov. 68. B. ficorum (Townsend). 69. B. flava sp. nov. 70. B. fortis (Rondani). 71. B. kolomyetzi Mesnil. 72. B. kurahashii sp. nov. Scale bars = 0.5 mm.

FIGURES 73 – 81. Billaea spp., heads of male in anterior view. 73. B. atkinsoni (Baranov). 74. B. brevicauda sp. nov. 75. B. carinata sp. nov. 76. B. chinensis sp. nov. 77. B. ficorum (Townsend). 78. B. flava sp. nov. 79. B. fortis (Rondani). 80. B. kolomyetzi Mesnil. 81. B. kurahashii sp. nov. Scale bars = 0.5 mm.